Inkjet printers typically utilize a printhead that includes an array of orifices (also called nozzles) through which ink is ejected on to paper or other print media. One or more printheads may be mounted on a movable carriage that traverses back and forth across the width of the paper feeding through the printer, or the printhead(s) may remain stationary during printing operations, as in a page width array of printheads. A printhead may be an integral part of an ink cartridge or part of a discrete assembly to which ink is supplied from a separate, often detachable ink container. For printhead assemblies that utilize detachable ink containers, it is important that the operative fluid connection between the outlet of the ink container and the inlet to the printhead assembly, commonly referred to as a fluid interconnection or “FI”, provide reliable ink flow from the container to the printhead assembly.
Ink is drawn from the ink container through a filter on the inlet to the printhead assembly. The inlet to the printhead assembly is commonly referred to as an inlet “tower” because it usually extends out from the surrounding structure. Poor contact between the wick at the outlet of the ink container and the filter at the inlet tower may impede proper ink flow. Air leaking into the printhead assembly at this fluid interconnection may also impede ink flow. Thus, it is desirable to protect the filter from damage that can occur during repeated installations and removals of the ink containers.
The inlet tower structure for a printhead assembly is usually assembled by staking a stainless steel mesh filter onto the top of the tower. The exposed edges of the filter, which may contain loose fibers where the filter is punched or otherwise cut from a sheet of fabric mesh, is particularly susceptible to damage. To prevent the edge of the filter from coming into direct contact with the outlet/snout on the ink container, and thus help prevent damage to the filter, the peripheral edge of the filter may be recessed into the tower so that the rim of the tower is significantly higher than the edge of the filter. It was thought that the higher tower rim would protect the filter from damaging contact with the container outlet. However, it has been observed that this recessed filter design cannot be relied on to protect the filter from damage while still allowing a robust fluid interconnection. If the rim is too high with respect to the filter, then the rim may prevent the wick in the container outlet from making full contact with the filter. If the rim is too low, then the edge of the filter may be exposed to the container outlet, creating a risk of damage during installation and removal of the container.